Styrene Suppression Application
Many approaches have been proposed for reducing styrene emission when unsaturated polyester resin has been utilized. Replacement of styrene with less volatile monomers is expensive and these monomers usually do not have the diluent characteristics that styrene possesses. Highly filled resin systems could not be used due to unrealistically high viscosities. The most popular method for styrene reduction is to develop low viscosity oligomers that can accommodate lower styrene levels without significant loss of physical properties or application properties. Although this approach does work with certain applications, closed mold and highly filled sprayable systems are difficult or impossible utilizing this approach. A third approach is to initiate a film with ultra-violet light. The film keeps the styrene in and air out. Lower styrene emission and faster resin cure is the result. Again, exposure to ultra-violet radiation of the resin system in cases cannot be accomplished in a practical way.